2002 MAZDA 6 battery

ELECTRONIC 4WD CONTROL SYSTEM
M–17
M
Memory function
•This function stores DTCs for malfunctions of the input/output signal systems as determined by the failure
detection function. Once a DTC is stored, it is not cleared even if the input/output signal system malfunction
returns to normal when the ignition key is turned to the LOCK position (engine OFF).
•Since DTCs are stored in the non-volatile memory inside the 4WD CM, they are not cleared even if the battery
is disconnected. Therefore, it is necessary to clear the memory when maintenance has been completed. For
clearing DTCs, refer to the procedures in the Workshop Manual.
•When inspecting DTCs using a WDS or equivalent, only one memory stored DTC at a time can be displayed.
Therefore, when multiple DTCs have been stored, it is necessary to inspect for DTCs again after repairing and
clearing the present DTC to ensure that there are no more DTCs present in the memory.
Fail-safe function
•When the failure detection function determines that there is a malfunction, the 4WD warning light illuminates to
alert the driver. At this time, the fail-safe function suspends control or takes other measures to ensure that
driving stability is not lost.
X:Available
*1: Does not illuminate when only the coupling torque request signal from the DSC HU/CM cannot be received.*2: Only integrated DSC control is prohibited when only the coupling torque request signal from the DSC HU/CM
cannot be received.
External tester communication function
•This function allows for the storing and clearing of DTCs due to a communication link between the 4WD CM
and an external tester.
End Of Sie
DTC Malfunction location4WD warning
lightconditionDTC stored in
memoryControl condition
P1887 System wiring Illuminated X Stop
P1888 Differential oil temperature sensor Illuminated X Stop
U0100 PCM communication system Illuminated X Stop
U0101 TCM communication system Illuminated X Stop
U0121 DSC communication system
Illuminated
*1X
Stop*2

GENERAL PROCEDURES
M–21
M
PRECAUTION (FRONT AND REAR AXLE)A6E631001018201Wheel and Tire Removal/Installation
1. The removal and installation procedures for the wheels and tires are not mentioned in this section. When a
wheel is removed, tighten it to 88—118 N·m {9.0—12.0 kgf·m, 65.0—87.0 ft·lbf}
Brake Line Disconnection/Connection
Caution
•Brake fluid will damage painted surfaces. If brake fluid gets on a painted surface, wipe it off
immediately.
1. Tighten the brake pipe flare nut using the SST (49 0259 770B). Be sure to modify the brake pipe flare nut
tightening torque to allow for use of a torque wrench-SST combination.
2. If any brake line has been disconnected any time during the procedure, add brake fluid, bleed the brakes, and
inspect for leakage after the procedure has been completed.
Suspension Arm Removal/Installation
1. Tighten any part of the suspension that uses rubber bushings only after vehicle has been lowered and
unloaded.
Note
•Unloaded: Fuel tank is full. Engine coolant and engine oil are at specified level. Spare tire, jack, and tools
are in designated position.
Connector Disconnection
1. Disconnect the negative (-) battery cable before disconnecting connectors.
Electronic Control 4WD System Parts
1. After servicing the electronic control 4WD system parts, verify that no DTC has been stored. Clear any DTCs
remaining in the memory.
End Of Sie
GENERAL PROCEDURES

ELECTRONIC 4WD CONTROL SYSTEM
M–65
M
DIFFERENTIAL OIL TEMPERATURE SENSOR INSPECTIONA6E632227100209
Warning
•Hot differential oil may cause severe burns. Do not perform maintenance while differential oil is
hot.
1. Disconnect the negative (-) battery cable.
2. Disconnect the differential oil temperature sensor connector and remove the differential oil temperature sensor.
3. Wrap the differential oil temperature sensor with
plastic wrap and immerse it into a beaker filled
with water. Gradually raise the water
temperature, and measure resistance between
differential oil temperature sensor terminals A and
B.
•If not as specified, inspect the harness for
continuity. If there is normal continuity
between the terminals, replace the differential
oil temperature sensor.
Specification
4. Install the differential oil temperature sensor and connect the connector.
5. Connect the negative (-) battery cable.
End Of Sie
DIFFERENTIAL OIL TEMPERATURE SENSOR REMOVAL/INSTALLATIONA6E632227100210
Warning
•Hot differential oil may cause severe burns. Do not perform maintenance while differential oil is
hot.
1. Disconnect the negative (-) battery cable.
2. Disconnect the differential oil temperature sensor connector.
3. Remove the differential oil temperature sensor.
4. Apply differential oil to the O-ring.
5. Install the differential oil temperature sensor.
Tightening torque
12.7—17.3 N·m {1.3—1.7 kgf·m, 9.4—12.7
ft·lbf}
6. Connect the differential oil temperature sensor
connector.
7. Connect the negative (-) battery cable.
End Of Sie
ELECTRONIC 4WD CONTROL SYSTEM
Water temperature (°C {°F}) Resistance (kirohm)
0 {32} 91—100
10 {50} 56—61
20 {68} 35—39
30 {86} 23—25
40 {104} 14—17
50 {122} 10—11
60 {140} 7.1—7.9
70 {158} 5.0—5.6
80 {176} 3.6—4.0
A B
A6J63222101
DIFFERENTIAL OIL
TEMPERATURE SENSOR
A6E63222102

M–66
ELECTRONIC 4WD CONTROL SYSTEM
4WD SOLENOID INSPECTIONA6E6322271002111. Disconnect the negative (-) battery cable.
2. Disconnect the 4WD solenoid connector.
3. Measure resistance between 4WD solenoid
connector terminals A and B.
•If the resistance is not within the specification,
replace the coupling unit.
Resistance
1.5—2.0 ohms
(Rear differential oil temperature at 20°C
{68°F})
4. Connect the 4WD solenoid connector.
5. Connect the negative (-) battery cable.
End Of Sie
4WD CONTROL MODURE INSPECTIONA6E632227100212
Note
•4WD CM terminal voltage can vary depending on measuring conditions and vehicle aging, resulting in
misdiagnosis. Therefore, it is necessary to perform an overall inspection of the input/output systems and
4WD CM to determine which part is malfunctioning.
•With the 4WD CM connector connected, measure voltage by connecting the voltmeter negative (-) lead to
the body ground and positive (+) lead to each 4WD CM terminal.
1. Measure voltage or resistance at each 4WD CM terminal using a voltmeter and an ohmmeter.
•If not as specified, replace the 4WD CM.
Terminal Voltage List (Reference)
A
B
A6J63222103
Terminal SignalInput/
outputConnected
toMeasuring
itemTest conditionVoltage (V)/
ContinuityInspection location
in case of failure
ADifferential oil
temperature
sensor signalInputDifferential oil
temperature
sensorVoltageIgnition
key
ONDifferential oil
temperature
20°C {68°F}3.0•Inspect
differential oil
temperature
sensor
•Inspect related
harness Differential oil
temperature
60°C {140°F}1.4
B——— ——— — —
CDifferential oil
temperature
sensor GND—Differential oil
temperature
sensorContinuity Any condition Yes•Inspect related
harness
D——— ——— — —
E——— ——— — —
F——— ——— — —
GCAN-HInput/
output—Perform measurement during DTC inspection.—
HCAN-LInput/
output—Perform measurement during DTC inspection.—
A
B C
D E
F G
H I
J K
L M
N O
P
A6J63222104

ELECTRONIC 4WD CONTROL SYSTEM
M–67
M
End Of Sie
4WD CONTROL MODURE REMOVAL/INSTALLATIONA6E6322271002131. Disconnect the negative (-) battery cable.
2. Remove the lower panel.
3. Remove in the order indicated in the table.
4. Install in the reverse order of removal.
.
End Of Sie
IPower supply
(Ignition
switch)Input Ignition key VoltageIgnition key ON B+•Inspect fuse
•Inspect related
harness Ignition key OFF 1.0 or below
J——— ——— — —
KPower supply
(Main)Input Battery Voltage Any condition B+•Inspect fuse
•Inspect related
harness
L——— ——— — —
M——— ——— — —
N Ground—Ground Voltage Any condition 0•Inspect related
harness
O4WD solenoid
(+)Output 4WD solenoid VoltageIgnition key ON B+•4WD solenoid
•Inspect related
harness Ignition key OFF 1.0 or below
P4WD solenoid
(-)Output 4WD solenoid VoltageIgnition key ON B+•4WD solenoid
•Inspect related
harness Ignition key OFF 1.0 or below Terminal SignalInput/
outputConnected
toMeasuring
itemTest conditionVoltage (V)/
ContinuityInspection location
in case of failure
31
2
31
2
7.8—10.8 {0.8—1.1, 5.6—7.9}
N·m {kgf·m, ft·lbf} 7.8—10.8 {0.8—1.1, 5.6—7.9}
L.H.D.
R.H.D.
A6E63222105
1 Connector
2Nut34WD CM

ON-BOARD DIAGNOSTIC
M–75
M
WIRING DIAGRAMA6E637027100201
End Of Sie
ON-BOARD DIAGNOSTIC
IGNITION SWITCH
BATTERY
DIFFERENTIAL OIL
TEMPERATURE
SENSOR4WD CM4WD SOLENOID ELECTRONIC CONTROL
COUPLING
CAN DRIVERINSTRUMENT CLUSTER
CAN-H
CAN-LPCM DSC HU/CM KO
P I
A
C
NH G
TCM
A6E63702002

ON-BOARD DIAGNOSTIC
M–77
M
DTC P1887A6E637027100203
Diagnostic procedure
DTC P1887 System wiring
DETECTION
CONDITION•Current detection circuit in 4WD CM detects current above specification for more than specified period.
•4WD CM detects that 4WD solenoid control signal differs from current detected at current detection
circuit for more than specified period.
•Relay voltage detection circuit detects that voltage does not concur with relay ON/OFF signal for more
than specified period.
POSSIBLE
CAUSE•Open circuit or short to GND in harness between battery and 4WD CM terminal K
•Open circuit or short to GND between 4WD CM terminal O and 4WD solenoid terminal B
•Open circuit between 4WD CM terminal P and 4WD solenoid terminal A
•Open circuit between 4WD CM terminal N and body GND
•Open or short circuit in 4WD CM internal circuit
•ENG+B (10A) fuse malfunction
•4WD solenoid malfunction
•4WD CM malfunction
•Poor connection of connectors (female terminals)
STEP INSPECTION ACTION
1INSPECT 4WD SOLENOID CONDITION
•Turn ignition key to OFF.
•Disconnect 4WD solenoid connector.
•Inspect 4WD solenoid.
(See M–66 4WD SOLENOID INSPECTION)
•Is it okay?Yes Go to next step.
No Replace 4WD solenoid, then go to Step 9.
2INSPECT 4WD SOLENOID TO 4WD CM
(POWER SUPPLY CIRCUIT) FOR OPEN
CIRCUIT
•Disconnect 4WD CM connector.
•Inspect for continuity between 4WD CM
terminal O and 4WD solenoid terminal B.
•Is there continuity?Yes Go to next step.
No Repair or replace harness for open circuit between 4WD CM
and 4WD solenoid, then go to Step 9.
A A
B C
D E
F G
H I
J K
L M
N O
PB K
O B
A
N P BATTERYFUSE (ENG+B 10 A)
4WD CM
4WD CM CONNECTOR4WD SOLENOID
4WD SOLENOID CONNECTOR RELAY

M–78
ON-BOARD DIAGNOSTIC
End Of Sie
3INSPECT 4WD SOLENOID TO 4WD CM
(POWER SUPPLY CIRCUIT) FOR SHORT TO
GROUND
•Inspect for continuity between 4WD CM
terminal O and ground.
•Is there continuity?Yes Repair or replace harness for short to ground between 4WD
CM and 4WD solenoid, then go to Step 9.
No Go to next step.
4INSPECT 4WD SOLENOID TO 4WD CM
(GROUND CIRCUIT) FOR OPEN CIRCUIT
•Inspect for continuity between 4WD CM
terminal P and 4WD solenoid terminal A.
•Is there continuity?Yes Replace 4WD CM, then go to next step.
No Repair or replace harness for open circuit between 4WD CM
and 4WD solenoid, then go to Step 9.
5INSPECT 4WD CM POWER SUPPLY CIRCUIT
FOR OPEN CIRCUIT
•Measure voltage between 4WD CM terminal
K and ground.
•Is voltage B+?Yes Replace 4WD CM, then go to Step 9.
No Go to next step.
6INSPECT 4WD CM TO BATTERY FOR OPEN
CIRCUIT
•Disconnect 4WD CM connector and battery
positive terminal.
•Inspect for continuity between 4WD CM
terminal K and battery positive terminal.
•Is there continuity?Yes Go to next step.
No Repair or replace harness for open circuit between 4WD CM
and battery positive terminal, then go to Step 9.
7INSPECT 4WD CM TO BATTERY FOR SHORT
TO GROUND
•Inspect for continuity between 4WD CM
terminal K and ground.
•Is there continuity?Yes Repair or replace harness for short to ground between 4WD
CM and battery positive terminal, then go to Step 9.
No Replace 4WD CM, then go to step 9.
8INSPECT FUSE CONDITION
•Turn ignition key to OFF.
•Is ENG+B fuse (10A) okay?Yes Go to next step.
No Replace fuse, then go to Step 9.
9VERIFY TROUBLESHOOTING COMPLETED
•Make sure to reconnect all disconnected
connectors.
•Clear DTC from memory.
(See M–76 Clearing DTCs Procedures)
•Drive vehicle.
•Is the same DTC present?Yes Replace 4WD CM, then go to next step.
No Go to next step.
10VERIFY AFTER REPAIR PROCEDURE
•Is there any other DTC present?Yes Go to applicable DTC inspection.
No Troubleshooting completed. STEP INSPECTION ACTION